I guess military tech always finds its way home. Pittsburgh city officials believe their police department's use of a Long Range Acoustic Device (LRAD) at last week's G20 protests was "the first time the sound cannon had been used publicly."

Police used the device to emit a painful shrill that forced demonstrators to cover their ears and withdraw while police threw tear gas and stun grenades. "Other law enforcement agencies will be watching to see how it was used," Pittsburgh's police bureau chief told the NY Times. "It served its purpose well."